Strainer filter for coffee making



Aug. 7, 1945. F. J. BURNHAM 2,381,104

STRAINER FILTER FOR COFFEE MAKING Filed May 10. 1943 FRANKJ BURNHAM,

INVENTQR.

Patented Aug. 7, 1945 Q I UNITED STATES PAT-EN T OFFICE s'rasmaa m'rsn FOB comamamo Frank J. semi-m, Los Angeles, Calif. Application May 10, 1943, Serial No. scam r "4 mm; (Cl. 210-182) I This invention relates to a strainer filter for Fig. 2 is a plan oi the filter element, se. as

coflee making. viewed from line 2--! or Fig. 1, onan enlarged More specifically'speaking'th'e invention perscale. v

tains to an improvement in cofi'ee makers of the P18. 3 is an elevation of a modification oi the pressure-vacuum type in which are utilized comfilter element per se. 4

municating upper and lower receptacles, water Referring in detail to the drawlng. the lower belng forced by heating, from, the lower to the receptacle I supports an upper rece tacle 8 or a upper receptacle where it comes into contactwith coflee maker having a downwardly extending finely ground'coii'ee to form liquid coilee by infunnel-like spout I integral therewith there be- ,iusion, whence said liquid coffee is drawn down 10 ing an annular rubber aasket 8 fitted within the by vacuum (produced by cooling) into the lower mouth oi said lower receptacle. these parts, sepreceptacle. arately considered, not being novel.

' The invention principally pertains to anew v The novel filter element providedby this invenarticle or manufacture consisting. oi a coil of a tlon consists of a single piece of plain wire which resilient character, between adjacent convoluis formed intopan approximately tubular coil, said tensioning of the coils,

The present invention further pertains to an steeply coiled conical upper end portion In improvement upon the strainer for coilee makers wherein the coils progressively decrease in didisclosed in United States Patent No. 2,225,027, ameter until they reach the produced axis or issued to Thomas J. Anders December 17, 1940, of the body portion of the coil, thus closing the upwhich the present applicantis the sole owner. per end of the coiled structure except for the It is an object or this invention to provide an presence of a client clearance between adjacentthe brewed c'ofi'ee while it is being drawn down- 5 This novel resilient filtering coil is made of wardly by suction from an upper to a lower. re-- stainless steel spring wire, which insures that the coils thereof accurately maintain themselves in Another object of the invention is to provide their relative positions, the coil being manufaca filtering coil which is easier to clean in a thortured in such a manner that adjacent coils, ough manner, and which may be so cleaned withp throughout the entire length of the spring, mainout removing it from the filtering position, and themselves slightly spaced apart, thereby without an objectionable forcing farther apart providing snsrromhelicehstreiner t II which the coils thereofv by traction, or otherwise. extends from end to end of the spring Said slit means, reducing the same to the minimum numthe brewed coflee, but it also" aids the user quickber of parts, namely, unity; to provide improved ly and thoroughly to clean the filter after use removed from the filtering position and which, 40 The upper, steeply conical end portion ill oi more quickly and conveniently placed in its opas a whole.

Other objects, advantages and features or incoil is shaped the same as the coil I but the wire ventionwillhereinaiter appear. strand oi the coil is extended at its upper end Refe ing to the lccom anying drawing, which to form a hook-shaped extension under which illustrates what is at present deemed to be a. premay be inserted a; finger oi the operator in order ierrecl embodiment of the invention, to apply upward traction to the coil in order to Fig. 1 is a vertical-mid-section oi the oasin withdraw it from the spout l of th open-t pped or the device, the filter element being shown uppercontainer 8 when the helical portion oi the therein as it appears irom all sides, 8 spring is positioned vertically with its open end iency oi the coil can be convolutions of directed downwardly. the center of gravity of said being in alinement with.

hook-shaped extension the axis or said coil and spout.

In both embodiments of the invention the resildepended upon to hold being extended from the axis or the coil in relation to the coil as a whole and formed into a hook-to receive a finger of the operator, when the helical portion of the spring is positioned yerit in its operativeposition in a dependable manher when the coil is inserted in place within the spout I with the smaller end of the long, gradual, taper directed downwardly. Also, in both em-. bodiments, a closing or the upper end of the coil (except for the presence of the strainer slit H), is effected by progressively decreasing the diameters of the convolutions in such a manner as has already been described.

The operation or the device will be readily understood from the foregoing description oi the invention, supplemented by the knowledge oi those skilled in the art to which the invention pertains.

It should be understood that the present disclosure is for the purpose or illustration only and .that this invention includes all modifications and equivalents which fall within the scope oi-the subject matter claimed.

What is claimed is;

1. As an article of manufacture, a filter for insertion into the downwardly directed spout of a cofiee maker receptacle, said filter consisting of a helical wire spring the convo utions of which are of such tensility as to m tain themselves normally upright without auxiliary support in a uniformly slightly spaced apart relation from end to end oi the helix, thereby providing a continuous coffee filtering slit ,while obstructing the passage of coflee grounds, said helical spring being open at one end and at its opposite end being closed against the passage of cofiee grounds, by reason oi its coils progressively decreasing in diameter and terminating at the axis or the coil as a whole.

2. As an article of manufacture, a filter element for insertion into the downwardly directed spout portion of a strainer receptacle, saidfilter element consisting of a helical wire spring the which maintain themselves normally in a uniformly slightly spaced apart relation to each other thereby providing a filtering slit, said helical spring being open at one end closed except for reason of its coils progresdiameterto the axis or the strand at the closed end and at its opposite end being said filtering slit, by sively decreasing in coil as a whole, the wire .60 tractioning oi the coil.

ment, with the axis 3. A filter for insertion into the downwardly.

tically with its --open end the center 0! gravity of said cell and spout.

directed spout portion of a coiieeunaker, said filter consisting of a helical'wire spring the can volutions of maintain themselves normally upright without auxiliary support in a uniformly slightly spaced apart relation to each other from end to end of the helix thereby providing a continuous coiiee filtering slit while obstructing the passage or coiiee grounds when vertically poised in filtering position in the mount oithe tunnel-like spout or a conventional coiIee maker oi the pressure vacuum type, said helical spring being open at one end and at its opposite end being closed exslit. by reason of its coilscept ior said filtering progressively decreasing in diameter to the axis of the coil as a whole.

4. A filter, for a coffee maker consisting of a,

single piece of plain wire formed into an approximately tubular coil, said coil having a slightly tapered body portion with an open lower end andfurnished with a more steeply coiled conical end portion wherein the coils progressively decrease in diameter until they reach the produced axis of the body portion of the coil as a whole, thereby closing the upper end oi .the coiled structure except for the presence of a slight clearance between adjacent coils, said coil being constructed in such a manner that adjacent coils throughout the entire length of the spring maintain themselves normally uniformly slightly spaced apart without auxiliary support in a vertical relation to the axis of the coil as a cient tensility to support the helical construction against lateral distortion and axial collapse due' to the'weight or superimposed coils, thereby providing a narrow,v helical strainer slit which extends from end to end or the prising the coil, said slit not only serving to strain out the granules from the brewed coflee, but also-aiding the user quickly and thoroughly to clean the filter after use without lengthwise mam: J. hummus.

directed downwardly. of said hook being in alinek which are or 'such tensility as to whole and with suiilspring wire com- 

